PHP (apache) is running as user nobody. The group cssteam is the group that modifies my css files.
I find that when I remove the "x" from the first column (user permissions), the css files in these folders are not available. How come? I mean, the folders are executable to everyone (x in the last column). Any ideas?

now do chmod a-rwx -R * (remove all premissions for everyone). do you know binary sistem (calculation). so take a paper place 1 where you want to enable the premission and 0 where you dont want.

example:
owner : r w x
1 0 0
in this case owner can only read and the number is 1
other users: r w x
1 0 1
in this case other users can read and execute so the number is 5
all users: r w x
0 0 0
so final it should be:
chmod 150 -R *
150 = 1 for reading owner ; 5 = 1+4 for read and execute :)

so if r is 1 the result is 1
if w is 1 the result is 2
if x is 1 the result is 4
if there is a 0 the result is 0